ESFRI, Astronomy & Astroparticles Panel Brussels, November 24, 2005

The KM3NeT Project:

A km

3

–Scale Mediterranean Neutrino Telescope and Deep-Sea Research Infrastructure

Uli Katz Univ. Erlangen on behalf of the KM3NeT consortium

   Scientific Case Technical Aspects The KM3NeT Design Study and Beyond  Conclusions and Outlook

The Principle of Neutrino Telescopes

  Role of the Earth: Screening against all particles except neutrinos.

Atmosphere = target for production of secondary neutrinos.

  Čerenkov light: In water: θ C ≈ 43° Spectral range used: ~ 350-500nm.

  Angular resolution in water: Better than ~0.3

° for neutrino energy above ~10 TeV, 0.1° at 100 TeV Dominated by angle( n,m ) below ~10 TeV (~0.6

° at 1 TeV) 24.11.2005

U. Katz: KM3NeT 2

Astro- and Particle Physics with

n

Telescopes

• • •

Low-energy limit: short muon range small number of photons detected background light from K40 decays

• •

High-energy limit: neutrino flux decreases like E –n (n ≈ 2) large detection volume needed.

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U. Katz: KM3NeT 3

Neutrinos from Astrophysical Point Sources

 Association of neutrinos to specific astrophysical objects .

 Energy spectrum, time structure, multi-messenger observations provide inside source .

insight into physical processes  Measurements profit from very good angular resolution of water Čerenkov telescopes.

 km

3

detectors needed to exploit the potential of neutrino astronomy .

All points and lines are upper flux limits Southern Sky Northern Sky

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Sky Coverage of Neutrino Telescopes

South Pole Mediterranean

Region of sky seen in galactic coordinates assuming efficiency for downward hemisphere.

Mkn 421 Mkn 501 Crab Not seen Mkn 501 RXJ1713 Crab SS433 Not seen SS433 Galactic Center VELA

→ We need n telescopes in both hemispheres to see the whole sky 24.11.2005

U. Katz: KM3NeT 5

High-energy

g

sources in the Galactic Disk

 5 g sources could be/are associated with SNR, e.g. RX J1713.7-3946;   Some coincide with EGRET, ASCA, … unidentified sources;  3 could be pulsar wind nebulae, typically displaced from the pulsar; 3 have no counterpart known to us.

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W. Hofmann, ICRC 2005

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Neutrinos from Supernova Remnants

Example: SNR RX J1713.7-3946 (shell-type supernova remnant) H.E.S.S. : E

g

=200 GeV – 40 TeV

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  Acceleration beyond 100 TeV.

Power-law energy spectrum, index ~2.1

–2.2.

U. Katz: KM3NeT  Spectrum points to hadron acceleration  n flux ~ g flux Typical n energies: few TeV 7

E Flux Sensitivity of the KM3NeT

n

Telescope

KM3NeT sensitivity estimated for



requirement: 10 hits/event

 

80% duty cycle

n m

flux Very preliminary !

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n m

23 events flux =

g

flux / 2

U. Katz: KM3NeT 8

Indirect Search for Dark Matter

 WIMPs can be gravitationally trapped in Earth, Sun or Galactic Center;  Neutrino production by χχ  ν  X  Detection requires low energy threshold (O(100GeV) or less).

  Flux from Galactic Center may be enhanced if a Black Hole is present → exciting prospects for KM3NeT [see e.g. P. Gondolo and J. Silk, PRL 83(1999)1719].

But: model uncertainties on n are orders of magnitude!

flux

Neutrino flux from the Galactic Center (from G. Bertone et al., astro-ph/0403322) Specific km 3 analysis not yet available.

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Diffuse

n

Flux: Models, Limits and Sensitivities

 At E n

RICE AGASA

be opaque for n ’s  required to look upwards;

Amanda, Baikal

Upward shielding important;

2002 2004 Extragalactic

g

p sources (Mannheim et al.) Gamma Ray Bursts (Waxman & Bahcall) 2007 2012



RICE GLUE

Time correlations can improve

Anita Topological defects (Sigl) Amanda,Antares AUGER (

n n t

oscillation corrected) , Baikal, Nestor AGN Jets (Mannheim) Auger + new technologies km 3

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Summary of KM3NeT physics goals

 Search for astrophysical point sources “Smoking gun” for identification of hadronic accelerators and investigation of acceleration mechanisms; Neutrino part of multi-messenger observations to correlate radiative and hadronic processes; Study of transient sources (e.g. Gamma Ray Bursts); Unique chance to study neutrinos from galactic disk .

 Measurement of the diffuse neutrino flux Information on cosmological source densities/distributions; Search for Big Bang relics.

 Dark Matter Search for neutrinos from WIMP annihilations.

 Particle physics & cosmology Magnetic monopoles, topological defects, Z bursts, nuclearites, … 24.11.2005

U. Katz: KM3NeT 11

Marine sciences

 Large interest for in the deep sea: long-term, real-time measurements Marine biology Geology and geophysics (seismology, tsunamis, …) Environmental sciences Oceanography …  KM3NeT will be associated to European deep-sea observatory network projects (ESONET, EMSO).

 Marine science communities are project preparation.

actively involved in the 24.11.2005

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Technical aspects

 3 current projects in the Mediterranean Sea provide Proof of feasibility; The world expertise in deep-sea neutrino telescope technology;  A huge reservoir of technical experience and solutions; Extensive exploration of 3 candidate sites.

The technical design of the KM3NeT n telescope will be worked out in an EU-funded 3-year Design Study Participation of all current deep-sea n telescope groups as well as “newcomers” and marine science institutes; EU contribution 9 M € , overall budget ~ 20 M € (contract signature in progress); Project start: February 1, 2006 .

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ANTARES: Detector Design

   

String-based detector; Underwater connections by deep-sea submersible; Downward-looking photomultipliers (PMs), axis at 45 O to vertical; 2500 m deep.

14.5m

100 m 25 storeys, 348 m ~70 m

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U. Katz: KM3NeT

Junction Box

14

ANTARES: MILOM (2005)

• Successful operation over several months • Major progress: •

Validation of final design;

•

Validation of time calibration (

D

t < 1 ns);

•

Validation of acoustic positioning (

D

x < 10 cm);

•

Measurements and long-term monitoring of environmental parameters;

•

Tests and improvements of data acquisition.

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    

NESTOR: Rigid Structures Forming Towers

Tower based detector (titanium structures).

Dry connections (recover−connect−redeploy).

Up- and downward looking PMs.

3800 m deep.

First floor (reduced size) deployed & operated in 2003.

Plan: Tower(s) with12 floors → 32 m diameter → → 30 m between floors 144 PMs per tower

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NESTOR: Measurement of the Muon Flux

NESTOR Coll., G Aggouras et al, Astropart. Phys. 23 (2005) 377

Atmospheric muon flux determination and parameterisation by dN d Ω  dt  ds  I 0  cos α θ 

I 0 = 4.7



= 9.0



0.5(stat.) 0.7(stat.) x 10 -9 cm -2 s

 

-1 0.2(syst.) 0.4(syst.) sr -1

(754 events)

Results agree nicely with previous measurements and with simulations.

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Zenith Angle (degrees

) U. Katz: KM3NeT 17

The NEMO Project

   Extensive site exploration (Capo Passero near Catania, depth 3500 m); R&D towards km

3

: architecture, mechanical structures, readout, electronics, cables ...; Simulation.

    Example: Flexible tower 16 arms per tower, 20 m arm length, arms 40 m apart; 64 PMs per tower; Underwater connections; Up- and downward-looking PMs.

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NEMO Phase I

Shore station

 Test site at 2000 m depth operational.

 Funding ok.

 Completion expected by 2006.

Geoseismic station SN-1 (INGV) 21 km e.o. Cable with single steel shield J 2.5 km e.o. Cable with double steel shield BU 5 km e.o. cable J J 5 km e.o. cable

 

10 optical fibres standard ITU- T G-652 6 electrical conductors



4 mm 2

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Aiming at a km

3

-Detector in the Mediterranean

HENAP Report to PaNAGIC, July 2002:

 “The observation of cosmic neutrinos above 100 GeV is of great scientific importance. ...“  “... a km

3

-scale detector in the Northern hemisphere should be built to complement the IceCube detector being constructed at the South Pole.”  “The detector should be of km

3

-scale, the construction of which is considered technically feasible.” 24.11.2005

U. Katz: KM3NeT 20

How to Design a km

3

Deep-Sea

n

Telescope

dilute scale up Large volume with same number of PMs?

• PM distance given by absorption length in water (~60 m) and PM properties • Efficiency loss 24.11.2005

: for larger spacing Existing telescopes “times 30” ?

• Too expensive • Too complicated (production, maintenance) • Not scalable (readout bandwidth, power, ...) R&D needed: • Cost-effective solutions to reduce price/volume by factor ~2 • Stability goal: maintenance-free detector • Fast installation time for construction & deployment less than detector life time • Improved components U. Katz: KM3NeT 21

The KM3NeT Vision

    KM3NeT will be a multidisciplinary research infrastructure : Data will be publicly available ; Implementation of specific online filter algorithms will yield particular sensitivity in predefined directions  non-KM3NeT members can apply for observation time ; Data will be buffered to respond to Deep-sea access for GRB alerts marine sciences .

KM3NeT will be a pan-European project 8 European countries involved in Design Study; etc.

Substantial funding already now from national agencies.

KM3NeT will be constructed in time to take data concurrently with IceCube .

KM3NeT will be extendable .

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KM3NeT Design Study: Participants

  Cyprus: Univ. Cyprus France: CEA/Saclay , CNRS/IN2P3 (CPP Marseille, IreS Strasbourg, APC Paris-7) , Univ. Mulhouse/GRPHE, IFREMER   Germany: Univ. Erlangen , Univ. Kiel Greece: HCMR , Hellenic Open Univ.

, NCSR Demokritos , NOA/Nestor , Univ. Athens  Italy: CNR/ISMAR , INFN (Univs. Bari, Bologna, Catania, Genova, Napoli, Pisa, Roma-1, LNS Catania, LNF Frascati) , INGV , Tecnomare SpA    Netherlands: NIKHEF/FOM (incl. Univ. Amsterdam, Univ. Utrecht, KVI Groningen) Spain: UK: IFIC/CSIC Valencia Univ. Aberdeen , , Univ. Valencia Univ. Leeds , , UP Valencia Univ. Liverpool , Univ. Sheffield

Particle/Astroparticle institutes (29) – Sea science/technology institutes (7) – Coordinator

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Objectives and Scope of the Design Study

     

Establish path from current projects to KM3NeT:

Critical review of current technical solutions; New developments, thorough tests; Comparative study of candidate sites (figure of merit: physics sensitivity / €); Assessment of quality control and assurance; Intensify and assess links to industry; Investigation of funding and governance models.

  

Major objectives:

Conceptual Design Report by summer 2007; Technical Design Report by February 2009 ; Limit overall cost to 200 M € per km

3

(excl. personnel).

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Some Key Questions

      Which architecture to use?

(strings vs. towers vs. new design)

All these questions are highly interconnected !

How to get the data to shore ?

(optical vs. electric, electronics off-shore or on-shore) How to calibrate the detector ?

(separate calibration and detection units?) Design of photo-detection units ?

(large vs. several small PMs, directionality, ...) Deployment technology ?

(dry vs. wet by ROV/AUV vs. wet from surface) And finally: path to site decision.

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Detector Architecture

(D. Zaborov at VLV

n

T)

200 m 24.11.2005

50 floors 20 m step 16 floors, 4 PMs each 40 m step U. Katz: KM3NeT 26

Sea Operations

   Rigid towers or flexible strings?

Connection in air (no ROVs) or wet mateable connectors?

Deployment from platform or boat?

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Photo Detection: Options

  Large photocathode area with arrays of small PMs packed into pressure housings – improved timing and amplitude resolution.

Determination of photon direction, e.g. via multi-anodic PMs plus a matrix of Winston cones.

 But: phase space for developments from scratch is too tight.

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Associated Sciences Node

Observatories 1 Array Data KM3NET Cable to shore

M. Priede, Sept. 2005

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2 Observatory Data Associated Sciences node Control Signals 3 Test Data Fixed Cable ROV Moveable tether Junction Box Test Site Junction Box U. Katz: KM3NeT 29

KM3NeT: Towards a Site Decision

 Final site decision involves scientific and political arguments (funding, host country support, …).

 Objective of Design Study: Provide scientific input and stimulate political discussion.

 Possible scenario: Similar to Pierre Auger Observatory (two candidate sites, decision based on commitment of host country).

 Relation of funding options to site choice will be explored in Design Study.

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KM3NeT: Path to Completion

Time schedule (partly speculative & optimistic):

01.02.2006

Mid-2007 February 2009 2009-2010 2010-2012 2011-20xx Start of Design Study Conceptual Design Report Technical Design Report Preparation Phase (possibly in FP7) Construction Data taking 24.11.2005

U. Katz: KM3NeT 31

Conclusions and Outlook

 A km

3

-scale neutrino telescope in the Mediterranean is required to exploit the potential of neutrino telescopy.

 The pilot projects prove the feasibility of deep-sea neutrino telescopes and provide a huge source of experience and technical solutions.

 The technical design will be worked out in a 3-year Design Study.

 KM3NeT will be a pan-European, interdisciplinary research infrastructure open to the entire community and the marines sciences.

 With KM3NeT, Europe will take the lead in neutrino astronomy.

24.11.2005

U. Katz: KM3NeT 32